Year-round observations of stable carbon isotopic composition of carboxylic acids, oxoacids and α-Dicarbonyls in fine aerosols at Tianjin, North China: Implications for origins and aging.

To better understand the origins and photochemical processing (aging) of organic aerosols (OA), we studied fine aerosols (PM) collected at urban (Nankai District (ND)) and suburban (Haihe Education Park (HEP)) Tianjin, North China over a one-year period (2018-2019) for stable carbon isotopic composition (δC) of water-soluble diacids, oxoacids, α-dicarbonyls and fatty acids. Maleic (M, -18.3 ± 10.

Distribution characteristics of organosulfates (OSs) in PM in Tianjin, Northern China: Quantitative analysis of total and three OS species.

Organosulfates (OSs) are important secondary organic aerosol (SOA) species in atmospheric fine particles (PM) and can be considered as molecular indicators of SOA. To understand their seasonal and diurnal distribution characteristics and formation mechanism in northern China, PM samples collected in daytime and nighttime in winter and summer 2019 in Tianjin, China were studied for total OSs and three OS species (methyl sulfate (MS), glycolic acid sulfate (GAS), benzyl sulfate (BS)). The S contents of total OSs (S) in winter and summer were 0.

Molecular characterization and spatial distribution of dicarboxylic acids and related compounds in fresh snow in China.

Low molecular weight organic compounds are ubiquitous in the atmosphere. However, knowledge on their concentrations and molecular distribution in fresh snow remains limited. Here, twelve fresh snow samples collected at eight sites in China were investigated for dicarboxylic acids and related compounds (DCRCs) including oxocarboxylic acids and α-dicarbonyls.

Why airborne transmission hasn't been conclusive in case of COVID-19? An atmospheric science perspective.

Airborne transmission is one of the routes for the spread of COVID-19 which is caused by inhalation of smaller droplets containing SARS-CoV-2 (i.e., either virus-laden particulate matter: PM and/or droplet nuclei) in an indoor environment.

Nitrogen Speciation and Isotopic Composition of Aerosols Collected at Himalayan Forest (3326 m a.s.l.): Seasonality, Sources, and Implications.

Nitrogenous aerosols are ubiquitous in the environment and thus play a vital role in the nutrient balance as well as the Earth's climate system. However, their abundance, sources, and deposition are poorly understood, particularly in the fragile and ecosensitive Himalayan and Tibetan Plateau (HTP) region. Here, we report concentrations of nitrogen species and isotopic composition (δN) in aerosol samples collected from a forest site in the HTP (i.

Modification of chitosan macromolecule and its mechanism for the removal of Pb(II) ions from aqueous environment.

It is well-known that heavy metals are non-biodegradable and have been showing remarkable impacts on the environment, public health and economics. Because of high toxic tendency, lead (Pb), is one of the foremost considerable hazardous metal with high environmental impacts. Chitosan is a polysaccharide, and can be utilized in wastewater treatment because of its good sorption ability.

Implications for biomass/coal combustion emissions and secondary formation of carbonaceous aerosols in North China.

To understand the origins, secondary formation and seasonality of carbonaceous aerosols in North China, we collected PM samples on day- and night-time bases in summer and winter 2016 from a typical metropolis, Tianjin, and studied their carbonaceous components and stable carbon isotope ratios of total carbon (δC). PM ranged from 21.2 μg m to 74.

Enrichment of C in diacids and related compounds during photochemical processing of aqueous aerosols: New proxy for organic aerosols aging.

To investigate the applicability of compound specific stable carbon isotope ratios (δC) of organics in assessment of their photochemical aging in the atmosphere, batch UV irradiation experiments were conducted on two ambient (anthropogenic and biogenic) aerosol samples in aqueous phase for 0.5-120 h. The irradiated samples were analyzed for δC of diacids, glyoxylic acid (ωC) and glyoxal.

Molecular distributions and compound-specific stable carbon isotopic compositions of lipids in wintertime aerosols from Beijing.

Molecular distributions and stable carbon isotopic compositions (δ(13)C) of n-alkanes, fatty acids and n-alcohols were investigated in urban aerosols from Beijing, northern China to better understand the sources and long-range atmospheric transport of terrestrial organic matter during polluted and clear days in winter. n-Alkanes (C19-C36), fatty acids (C8-C32) and n-alcohols (C16-C32) detected in Beijing aerosols are characterized by the predominance of C23, C16 and C28, respectively. Carbon preference index (CPI) values of n-alkanes, the ratios of the sum of odd-numbered n-alkanes to the sum of even-numbered n-alkanes, are close to 1, indicating a heavy influence of fossil fuel combustion.